<?php

/**
 * HTTP访问类
 */

namespace dux\lib;

class Http {

	/**
	 * 访问方式
	 * @var integer
	 */
	static public $way = 0;
	
	/**
	 * 设置访问方式
	 * @param integer $way 访问方式
	 */
	static public function setWay($way) {
		self::$way=intval($way);
	}

	/**
	 * 自动获取访问方法
	 * @return integer
	 */
	static public function getSupport() {
		//如果指定访问方式，则按指定的方式去访问
		if( isset(self::$way) && in_array(self::$way, array(1,2,3)) ) return self::$way;
		//自动获取最佳访问方式	
		if(function_exists('curl_init')){
			//curl方式
			return 1;
		} else if(function_exists('fsockopen')){
			//socket
			return 2;
		} else if(function_exists('file_get_contents')){
			//php系统函数file_get_contents
			return 3;
		} else {
			return 0;
		}	
	}
	
	/**
	 * GET数据
	 * @param  string  $url     访问地址
	 * @param  integer $timeout 超时秒
	 * @param  string  $header  头信息
	 * @return string
	 */
	static public function doGet($url,$timeout=5,$header="") {	
		if(empty($url)||empty($timeout))
			return false;
		if(!preg_match('/^(http|https)/is',$url))
			$url="http://".$url;
		$code=self::getSupport();
		switch($code)
		{
			case 1:return self::curlGet($url,$timeout,$header);break;
			case 2:return self::socketGet($url,$timeout,$header);break;
			case 3:return self::phpGet($url,$timeout,$header);break;
			default:return false;	
		}
	}
	
	/**
	 * POST数据
	 * @param  string  $url       发送地址
	 * @param  array   $post_data 发送数组
	 * @param  integer $timeout   超时秒
	 * @param  string  $header    头信息
	 * @return string
	 */
	static public function doPost($url, $post_data=array(), $timeout=5,$header="") {
		if(empty($url)||empty($timeout))
			return false;
		if(!preg_match('/^(http|https)/is',$url))
			$url="http://".$url;
		$code=self::getSupport();
		switch($code)
		{
			case 1:return self::curlPost($url,$post_data,$timeout,$header);break;
			case 2:return self::socketPost($url,$post_data,$timeout,$header);break;
			case 3:return self::phpPost($url,$post_data,$timeout,$header);break;
			default:return false;	
		}
	}	

	/**
	 * CURL GET数据
	 * @param  string  $url     访问地址
	 * @param  integer $timeout 超时秒
	 * @param  string  $header  头信息
	 * @return string
	 */
	static public function curlGet($url,$timeout=5,$header="") {
		$header=empty($header)?self::defaultHeader():$header;
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
		curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
		curl_setopt($ch, CURLOPT_REFERER, $_SERVER['HTTP_HOST']);
		curl_setopt($ch, CURLOPT_HTTPHEADER, array($header));//模拟的header头
		$result = curl_exec($ch);
		curl_close($ch);
		return $result;
	}

	/**
	 * CURL POST数据
	 * @param  string  $url       发送地址
	 * @param  array   $post_data 发送数组
	 * @param  integer $timeout   超时秒
	 * @param  string  $header    头信息
	 * @return string
	 */
	static public function curlPost($url, $post_data=array(), $timeout=5,$header="") {
		$header=empty($header)?'':$header;
		$post_string = http_build_query($post_data);  
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_POST, true);
		curl_setopt($ch, CURLOPT_POSTFIELDS, $post_string);
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
		curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
		curl_setopt($ch, CURLOPT_REFERER, $_SERVER['HTTP_HOST']);
		curl_setopt($ch, CURLOPT_HTTPHEADER, array($header));//模拟的header头
		$result = curl_exec($ch);
		curl_close($ch);
		return $result;
	}
	
	/**
	 * socket GET数据
	 * @param  string  $url     访问地址
	 * @param  integer $timeout 超时秒
	 * @param  string  $header  头信息
	 * @return string
	 */
	static public function socketGet($url,$timeout=5,$header="") {
		$header=empty($header)?self::defaultHeader():$header;
		$url2 = parse_url($url);
		$url2["path"] = isset($url2["path"])? $url2["path"]: "/" ;
		$url2["port"] = isset($url2["port"])? $url2["port"] : 80;
		$url2["query"] = isset($url2["query"])? "?".$url2["query"] : "";
		$host_ip = @gethostbyname($url2["host"]);

		if(($fsock = fsockopen($host_ip, $url2['port'], $errno, $errstr, $timeout)) < 0){
			return false;
		}
		$request =  $url2["path"] .$url2["query"];
		$in  = "GET " . $request . " HTTP/1.0\r\n";
		if(false===strpos($header, "Host:"))
		{	
			 $in .= "Host: " . $url2["host"] . "\r\n";
		}
		$in .= $header;
		$in .= "Connection: Close\r\n\r\n";
		
		if(!@fwrite($fsock, $in, strlen($in))){
			@fclose($fsock);
			return false;
		}
		return self::GetHttpContent($fsock);
	}

	/**
	 * socket POST数据
	 * @param  string  $url       发送地址
	 * @param  array   $post_data 发送数组
	 * @param  integer $timeout   超时秒
	 * @param  string  $header    头信息
	 * @return string
	 */
	static public function socketPost($url, $post_data=array(), $timeout=5,$header="") {
		$header=empty($header)?self::defaultHeader():$header;
		$post_string = http_build_query($post_data);  
		$url2 = parse_url($url);
		$url2["path"] = ($url2["path"] == "" ? "/" : $url2["path"]);
		$url2["port"] = ($url2["port"] == "" ? 80 : $url2["port"]);
		$host_ip = @gethostbyname($url2["host"]);
		$fsock_timeout = $timeout; //超时时间
		if(($fsock = fsockopen($host_ip, $url2['port'], $errno, $errstr, $fsock_timeout)) < 0){
			return false;
		}
		$request =  $url2["path"].($url2["query"] ? "?" . $url2["query"] : "");
		$in  = "POST " . $request . " HTTP/1.0\r\n";
		$in .= "Host: " . $url2["host"] . "\r\n";
		$in .= $header;
		$in .= "Content-type: application/x-www-form-urlencoded\r\n";
		$in .= "Content-Length: " . strlen($post_string) . "\r\n";
		$in .= "Connection: Close\r\n\r\n";
		$in .= $post_string . "\r\n\r\n";
		unset($post_string);
		if(!@fwrite($fsock, $in, strlen($in))){
			@fclose($fsock);
			return false;
		}
		return self::GetHttpContent($fsock);
	}

	/**
	 * file_get_contents GET数据
	 * @param  string  $url     访问地址
	 * @param  integer $timeout 超时秒
	 * @param  string  $header  头信息
	 * @return string
	 */
	static public function phpGet($url,$timeout=5,$header="") {
		$header=empty($header)?self::defaultHeader():$header;
		$opts = array( 
				'http'=>array(
							'protocol_version'=>'1.0', //http协议版本(若不指定php5.2系默认为http1.0)
							'method'=>"GET",//获取方式
							'timeout' => $timeout ,//超时时间
							'header'=> $header)
				  ); 
		$context = stream_context_create($opts);    
		return  @file_get_contents($url,false,$context);
	}

	/**
	 * file_get_contents POST数据
	 * @param  string  $url       发送地址
	 * @param  array   $post_data 发送数组
	 * @param  integer $timeout   超时秒
	 * @param  string  $header    头信息
	 * @return string
	 */
	static public function phpPost($url, $post_data=array(), $timeout=5,$header="") {
		$header=empty($header)?self::defaultHeader():$header;
		$post_string = http_build_query($post_data);  
		$header.="Content-length: ".strlen($post_string);
		$opts = array( 
				'http'=>array(
							'protocol_version'=>'1.0',//http协议版本(若不指定php5.2系默认为http1.0)
							'method'=>"POST",//获取方式
							'timeout' => $timeout ,//超时时间 
							'header'=> $header,  
							'content'=> $post_string)
				  ); 
		$context = stream_context_create($opts);    
		return  @file_get_contents($url,false,$context);
	}
	
	/**
	 * 默认HTTP头
	 * @return string
	 */
	static private function defaultHeader() {
		$header="User-Agent:Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12\r\n";
		$header.="Accept:text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n";
		$header.="Accept-language: zh-cn,zh;q=0.5\r\n";
		$header.="Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7\r\n";
		return $header;
	}
	
	/**
	 * 获取通过socket方式get和post页面的返回数据
	 * @param string
	 */
	static private function GetHttpContent($fsock=null)
	{
		$out = null;
		while($buff = @fgets($fsock, 2048)){
			 $out .= $buff;
		}
		fclose($fsock);
		$pos = strpos($out, "\r\n\r\n");
		$head = substr($out, 0, $pos);    //http head
		$status = substr($head, 0, strpos($head, "\r\n"));    //http status line
		$body = substr($out, $pos + 4, strlen($out) - ($pos + 4));//page body
		if(preg_match("/^HTTP\/\d\.\d\s([\d]+)\s.*$/", $status, $matches))
		{
			if(intval($matches[1]) / 100 == 2)
			{
				return $body;  
			}
			else
			{
				return false;
			}
		}
		else
		{
			return false;
		}
	}

    /**
     * 下载文件
     * @param  string  $filename 文件名
     * @param  string  $showname 显示文件名
     * @param  integer $expire   缓存时间
     * @return boolean
     */
    static public function download($filename, $showname='',$expire=1800) {
        if(file_exists($filename)&&is_file($filename)) {
            $length = filesize($filename);
        }else {
          die('下载文件不存在！');
        }
        $finfo = new \finfo(FILEINFO_MIME);
	    $type = $finfo->file($filename);
        //发送Http Header信息 开始下载
        header("Pragma: public");
        header("Cache-control: max-age=".$expire);
        //header('Cache-Control: no-appstore, no-cache, must-revalidate');
        header("Expires: " . gmdate("D, d M Y H:i:s",time()+$expire) . "GMT");
        header("Last-Modified: " . gmdate("D, d M Y H:i:s",time()) . "GMT");
        header("Content-Disposition: attachment; filename=".$showname);
        header("Content-Length: ".$length);
        header("Content-type: ".$type);
        header('Content-Encoding: none');
        header("Content-Transfer-Encoding: binary" );
        readfile($filename);
        return true;
    }
    
}